The present invention relates to propylene polymers containing from 0 to 2.5% by weight of C2-C10-olefin comonomers and having an Mw of from 350,000 to 1,000,000 g/mol, an Mw/Mn of from 4 to 10, a proportion by weight of the polymer fraction having a viscosity number of from 500 to 1400 ml/g of from 20 to 80% of the total polymer and a proportion by weight of a polymer fraction having a viscosity number of from 200 to 400 ml/g, of from 80 to 20% of the total polymer and an isotactic sequence length of from 50 to 100.
The present invention further relates to the use of such propylene polymers (hereinafter referred to as xe2x80x9cpropylene polymers of the present inventionxe2x80x9d) for producing fibers, films and moldings, in particular for producing tubes having a high creep rupture strength under internal pressure (creep rupture strength hereinafter referred to as xe2x80x9cCRSxe2x80x9d), the fibers, films and moldings, in particular the tubes having a high CRS, made from the propylene polymers of the present invention and the use of the moldings, in particular the tubes having a high CRS, in the construction of chemical apparatus, as drinking water pipe and as wastewater pipe.
High molecular weight propylene polymers can be prepared using conventional Ziegler catalysts based on a titanium compound/an aluminum alkyl, as is described, for example, in DE-A 40 19 053. The expression xe2x80x9chigh molecular weight propylene polymersxe2x80x9d usually refers to propylene polymers which have a molecular weight Mw measured by GPC (gel permeation chromatography) of more than about 500,000 g/mol and a corresponding melt flow rate at 230xc2x0 C. under a load of 5 kg (MFR 230/5, measured in accordance with ISO 1133) of at least about 3 dg/min. In contrast thereto, customary propylene polymers have an Mw of from about 100,000 g/mol to about 300,000 g/mol and correspondingly an MFR (230/5) of more than 4 dg/min.
The high molecular weight propylene polymers obtainable using Ziegler catalysts (hereinafter referred to as xe2x80x9chigh molecular weight Ziegler propylene polymersxe2x80x9d) generally have a large mean length of isotactic sequences xe2x80x9cn-isoxe2x80x9d, (measured using the 13C-NMR method as described by zambelli et al. Macromolecules 8, 687-689(1975); the value is usually over 100. Further properties of such high molecular weight Ziegler propylene polymers are a comparatively high proportion of xylene-soluble substances xe2x80x9cXS valuexe2x80x9d (XS value determined as described in the examples) and a comparatively high melting point of generally more than 160xc2x0 C. (determined by the DSC method, as described in the examples). When processed, for example by extrusion, to produce shaped articles such as tubes, etc., such high molecular weight Ziegler propylene polymers display poor processability (in particular poor flow) and the articles produced often have poor organoleptic properties (odor, taste). The unsatisfactory organoleptic properties are caused, on the basis of present-day knowledge, by low molecular weight, oily propylene oligomers.
Attempts are usually made to circumvent the unsatisfactory processability of the high molecular weight Ziegler propylene (homo)polymers by changing to high molecular weight Ziegler propylene-olefin copolymers which have a lower melting point and therefore flow more readily at a given temperature during extrusion than do the analogous homopolymers. However, the copolymers have an increased content of readily soluble propylene oligomers, again resulting in high proportions of xylene-soluble material and unfavorable organoleptic properties of the high molecular weight Ziegler propylene copolymers.
In addition, the tubes produced from high molecular weight Ziegler propylene polymers, for example as described in DE-A 40 19 053, have high brittleness (low CRS) and a rough (internal) surface. The rough surface provides, on the basis of present-day knowledge, a large surface area for attack by liquids, and the liquids leach out the polymer stabilizer present in the tube, which once again reduces the CRS of the tubes.
It is an object of the present invention to find propylene polymers which can easily be processed (inter alia due to improved flow) by means of conventional manufacturing tools to give shaped bodies, in particular tubes, which have not only low brittleness and a smooth surface but also a high toughness and good stiffness combined with a good CRS of the shaped bodies, in particular tubes.
We have found that this object is achieved by the propylene polymers of the present invention, the use of such propylene polymers for producing fibers, films and moldings, the fibers, films and moldings made of the propylene polymers of the present invention and the use of the tubes in the construction of chemical apparatus, as drinking water pipes and as wastewater pipes.
The propylene polymers of the present invention are generally obtained by means of at least two-stage polymerization (known as the cascade method) of propylene together with from 0 to 2.5% by weight of C2-C10-olefin comonomers, preferably from 0 to 1.5% by weight of C2-C10-olefin comonomers and in particular from 0 to 1% by weight of C2-C10-olefin comonomers, in the presence of metallocene catalyst systems (as described below).
Suitable C2-C10-olefin comonomers are ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene. It is possible to copolymerize a plurality of comonomers or only one comonomer with the propylene. The abovementioned % by weight are then based on the sum of the comonomers. Preferred C2-C10-olefin comonomers are ethylene, 1-butene and 1-hexene. Preferred propylene-olefin copolymers are propylene-ethylene copolymers, propylene-1-butene copolymers and propylene-ethylene-1-butene terpolymers. The total amount of comonomers in these cases, too, is in the range from 0.1 to 2.5% by weight, preferably in the range from 0.1 to 1.5% by weight, in particular in the range from 0.1 to 1% by weight.
The polymerization reactions, generally at least two-stage reactions, can essentially be carried out continuously or batchwise by all suitable olefin polymerization methods. They can be carried out in the gas phase, for example in a fluidized-bed reactor or a stirred gas phase, in the liquid monomers, in solution or in suspension in suitable reaction vessels or in loop reactors. The polymerization temperature is usually in the range from 0 to 150xc2x0 C., preferably in the range from 30 to 100xc2x0 C., the pressure is in the range from 5 to 500 bar, preferably from 10 to 100 bar, and the mean residence time is in the range from 0.5 hour to 6 hours, preferably from 0.5 to 4 hours.
A well-suited polymerization method is the two-stage bulk polymerization process.
Here, a high molecular weight propylene homopolymer or copolymer of the composition described above, preferably a propylene homopolymer, having a viscosity of from 500 to 1400 ml/g (determined by the method disclosed in the examples) and a proportion of the total polymer of from 20 to 80% by weight, preferably from 45 to 75% by weight, particularly preferably from 48 to 65% by weight, is prepared in the first reaction step, while in the second, usually downstream reaction step, a low molecular weight propylene homopolymer or copolymer of the composition described above, preferably a propylene homopolymer, having a viscosity of from 200 to 400 ml/g and a proportion of from 20 to 80% by weight, preferably from 25 to 55% by weight, particularly preferably from 35 to 52% by weight, is prepared.
The first and second reaction steps can be carried out batchwise or continuously. Preference is given to continuous operation. The first polymerization step is generally carried out in liquid propylene at from 55 to 100xc2x0 C. and a residence time of from 0.5 to 3.5 hours. A phase ratio in the range from 2.5 to 4 l of liquid propylene per kg of PP, preferably 3.3 l of liquid propylene per kg of PP, is usually set. To regulate the molar mass, hydrogen is generally metered in.
After the first reaction step, the multiphase system is generally transferred to the second reaction step and polymerized there at from 55 to 100xc2x0 C. The second reaction step generally takes place in a second reactor. There, a phase ratio of from 1 to 2.5 l of liquid propylene per kg of PP, preferably 1.9 l of liquid propylene per kg of PP, is usually set.
According to the present invention, different phase ratios are preferably set in the two reactors in the process described here. Ethylene and hydrogen are likewise metered in, as described above.
The temperatures and hydrogen concentrations in the two reactors may be identical or different. Suitable reactors are stirred vessels or loop reactors.
It is possible to depressurize the monomer between the two reactors and to introduce the still polymerization-active catalyst/polymer system into the second reactor. In the second reactor, it is possible to set a lower hydrogen concentration than in the first reactor.
The propylene polymers of the present invention have a mean molecular weight M, (determined by gel permeation chromatography at 135xc2x0 C. in 1,3,4-trichlorobenzene as solvent using a PP standard) of from 350,000 g/mol to 1,000,000 g/mol, preferably from 350,000 g/mol to 800,000 g/mol and in particular from 400,000 to 650,000 g/mol.
The molecular weight distribution Mw/Mn (determined by gel permeation chromatography at 135xc2x0 C. in 1,3,4-trichlorobenzene as solvent using a PP standard) of the propylene polymers of the present invention is in the range from 4 to 10, preferably in the range from 4 to 8.
The isotactic sequence length n-iso of the propylene polymers of the present invention (determined as described at the outset) is in the range from 50 to 100, preferably in the range from 55 to 95 and in particular in the range from 60 to 90.
According to the present invention, preference is given to products having an MFR (230/5), determined in accordance with ISO 1133, of from 0.01 to 5 dg/min, particularly preferably from 0.02 to 2 dg/min.
The propylene polymers of the present invention having the composition as described above can be fractionated by customary methods of polymer fractionation to give at least two fractions which have different viscosities, viz. molecular weights Mw. The high molecular weight fraction of the propylene homopolymer or copolymer, preferably propylene homopolymer, of the present invention generally has a viscosity (=VN) of from 500 to 1400 ml/g (determined by the method disclosed in the examples) and a proportion of the total polymer of from 20 to 80% by weight, preferably from 45 to 75% by weight, particularly preferably from 48 to 65% by weight.
The low molecular weight fraction of the propylene homopolymer or copolymer, preferably propylene homopolymer, of the present invention generally has a viscosity VN of from 200 to 400 ml/g and a proportion of the total polymer of from 20 to 80% by weight, preferably from 25 to 55% by weight, particularly preferably from 35 to 52% by weight.
On the basis of present-day knowledge, this narrow weight distribution spectrum of the different fractions of the propylene polymers of the present invention makes a large contribution to the improved properties (especially the CRS) of the fibers, films and especially moldings (e.g. tubes) which can be produced from the propylene polymers of the present invention.
The propylene polymer of the present invention obtained after the polymerization reaction is usually admixed with stabilizers, lubricants, fillers, pigments, etc., and granulated.
The polymerization of the propylene, if desired together with the comonomers described, takes place, preferably in the processes described, in the presence of metallocene catalyst Systems. The metallocene catalyst systems usually comprise a metallocene component A), a cocatalyst (also known as activator) B) and, if desired, support materials C) and/or organometallic compounds D) as scavengers.
As metallocene component A) of the metallocene catalyst system, it is in principle possible to use any metallocene which, under the specified polymerization conditions, produces isotactic polypropylene having a sufficiently high molar mass, i.e. an Mw of generally greater than 350,000 g/mol, and a sufficiently high melting point, i.e. generally greater than 150xc2x0 C.
The metallocene can be either bridged or unbridged and have identical or different ligands. Preference is given to metallocones of groups IVb of the Periodic Table of the Elements, namely of titanium, zirconium or hafnium.
It is of course also possible to employ mixtures of different metallocenes as component A).
Well-suited metallocene components A) are those described, for example, in DE-A 196 06 167, which is hereby expressly incorporated by reference. Particular mention may be made of the disclosure on page 3, line 28 to page 6, line 48 of DE-A 196 06 167.
Preferred metallocene components A) are those of the formula (I) below 
where
M1 is a metal of group IVb of the Periodic Table of the Elements,
R1 and R2 are identical or different and are each a hydrogen atom, C1-C10-alkyl group, a C1-C10-alkoxy group, a C6-C20-aryl group, a C6-C10-aryloxy group, a C2-C10-alkenyl group, an OH group, an NR122 group, where R12 is a C1-C2-alkyl group or a C6-C14-aryl group, or a halogen atom,
R3 to R8 and R3xe2x80x2 to R8xe2x80x2 are identical or different and are each a hydrogen atom, a C1-C40-hydrocarbon group which may be linear, cyclic or branched, e.g. a C1-C10-alkyl group, a C2-C10-alkenyl group, a C6-C20-aryl group, a C7-C40-arylalkyl group, a C7-C40-alkylaryl group or a C8-C40-arylalkenyl group, or adjacent radicals R4 to R8 and/or R4xe2x80x2 to R8xe2x80x2 together with the atoms connecting them form a ring system,
R9 is a bridge, preferably 
R10 and R11 are identical or different and are each a hydrogen atom, a halogen atom or a C1-C40 group such as a C1-C20-alkyl group, a C1-C10-fluoroalkyl group, a C1-C10-alkoxy group, a C6-C14-aryl group, a C6-C10-fluoroaryl group, a C6-C10-aryloxy group, a C2-C10-alkenyl group, a C7-C40-aralkyl group, a C7-C40-alkylaryl group or a C8-C10-arylalkenyl group or R10 and R11 together with the atoms connecting them form one or more rings and x is an integer from zero to 18,
M2 is silicon, germanium or tin, and the rings A and B are identical or different, saturated, unsaturated or partially saturated.
R9 can also link two units of the formula I with one another.
In formula I, it is particularly preferred that
M1 is zirconium or hafnium,
R1 and R2 are identical and are methyl or chlorine, in particular chlorine, and R9=M2R10R11, where M2 is silicon or germanium and R10 and R11 are each a C1-C20-hydrocarbon group such as C1-C10-alkyl or C6-C14-aryl.
The indenyl or tetrahydroindenyl ligands of the metallocones of the formula I are preferably substituted in the 2 position, 2,4 positions, 4,7 positions, 2,6 positions, 2,4,6 positions, 2,5,6 positions, 2,4,5,6 positions or 2,4,5,6,7 positions, in particular in the 2,4 positions. Preferred substituents are C1-C4-alkyl groups such as methyl, ethyl or isopropyl or C6-C20-aryl groups such as phenyl, naphthyl or mesityl. The 2 position is preferably substituted by a C1-C4-alkyl group such as methyl or ethyl. If the 2,4 positions are substituted, then
R5 and R5xe2x80x2 are preferably identical or different and are each a C6-C10-aryl group, a C7-C10-arylalkyl group, a C7-C40-alkylaryl group or a C8-C40-arylalkenyl group.
The following nomenclature is employed for the site of substitution: 
Further metallocones of particular importance are those of the formula I in which the substituents in the 4 and 5 positions of the indenyl radicals (R5 and R6 or R5xe2x80x2 and R6xe2x80x2) together with the atoms connecting them form a ring system, preferably a six-membered ring. This fused-on ring system can likewise be substituted by radicals having the meanings of R3-R8. An example of such a compound I is dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride.
Particular preference is given to compounds of the formula I which bear a C6-C20-aryl group in the 4 position and a C1-C4-alkyl group in the 2 position. An example of such a compound of the formula I is dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride.
Examples of metallocone components A in the process of the present invention are:
dimethylsilanediylbis(indenyl)zirconium dichloride
dimethylsilanediylbis(4-naphthylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methylbenzoindenyl)zirconium dichloride
dimethylsilanediylbis(2-methylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(p-tert-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-t-butylindenylzirconium dichloride
dimethylsilanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-ethylindenyl)zirconium dichloride
dimethylsilanediylbis (2-methyl-4-xcex1-acenaphthindenyl)zirconium dichloride
dimethylsilanediylbis(2,4-dimethylindenyl)zirconium dichloride
dimethylsilanediylbis(2-ethylindenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-thylindenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4,5-diisopropylindenyl)zirconium dichloride
dimethylsilanediylbis(2,4,6-trimethylindenyl)zirconium dichloride
dimethylsilanediylbis(2,5,6-trimethylindenyl)zirconium dichloride
dimethylsilanediylbis(2,4,7-trimethylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-5-isobutylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-5-t-butylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-phenanthrylindene)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-phenanthylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4,6-diisopropylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4,5-(methylbenzo)indenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4,5-(tetramethylbenzo)-indenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4-acenaphthindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-5-isobutylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4-phenanthrylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-ethyl-4-phenanthrylindenyl)zirconium dichloride
1,2-ethanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride
1,4-butanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride
1,2-ethanediylbis(2-methyl-4,6-diisopropylindenyl)zirconium dichloride
1,4-butanediylbis(2-methyl-4-isopropylindenyl)zirconium dichloride
1,4-butanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride
1,2-ethanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride
1,2-ethanediylbis(2,4,7-trimethylindenyl)zirconium dichloride
1,2-thanediylbis(2-methylindenyl)zirconium dichloride
1,4-butanediylbis(2-methylindenyl)zirconium dichloride
bis(butylcyclopentadienyl)Zr+CH2CHCHCH2B-(C6F5)3 
bis(methylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)Zr30 CH2CHCHCH2B-(C6F5)3 
1,2-ethanediylbis(2-methylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
1,4-butanediylbis(2-methylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
dimethylsilanediylbis(2-ethyl-4-phenylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
dimethylsilanediylbis(2-methyl-4-phenylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)Zr+CH2CHxe2x80x94CHCH2B-(C6F5)3 
dimethylsilanediylbis(2-methyl-4-phenylindenyl)Zr+CH2CHCHCH2B-(C6F5)3 
dimethylsilanediylbis(indenyl)Zr+CH2CHCHCH2B-(C6F5)3 
dimethylsilanediyl(tert-butylamino)(tetramethylcyclopentadienyl)zirconium dichloride
[tris(pentafluorophenyl)(cyclopentadienylidene)borato](cyclo-pentadienyl)-1,2,3,4-tetraphenylbuta-1,3-dienylzirconium
dimethylsilanediyl[tris(pentafluorophenyl)(2-methyl-4-phenyl-indenylidene)borato](2-methyl-4-phenylindenyl)-1,2,3,4-tetra-phenylbuta-1,3-dienylzirconium dimethylsilanediyl-[tris(trifluoromethyl)(2-methylbenzindenyl-iden)borato](2-methylbenzindenyl)-1,2,3,4-tetraphenylbuta-1,3-dienylzirconium
dimethylsilanediyl-[tris(pentafluorophethyl)(2-methyl-indenyl-iden)borato](2-methylindenyl)-1,2,3,4-tetraphenylbuta-1,3-dienylzirconium
dimethylsilanediylbis(indenyl)dimethylzirconium
dimethylsilanediylbisC4-naphthylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methylbenzoindenyl)dimethylzirconium
dimethylsilanediylbis(2-methylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-(2-naphthyl)indenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-t-butylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-isopropylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-ethylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-xcex1-acenaphthindenyl)dimethylzirconium
dimethylsilanediylbis(2,4-dimethylindenyl)dimethylzirconium
dimethylsilanediylbis(2-ethylindenyl)dimethylzirconium
dimethylsilanediylbis(2-ethyl-4-ethylindenyl)dimethylzirconium
dimethylsilanediylbis(2-ethyl-4-phenylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4,5-diisopropylindenyl)dimethylzirconium
dimethylsilanediylbis(2,4,6-trimethylindenyl)dimethylzirconium
dimethylsilanediylbis(2,5,6-trimethylindenyl)dimethylzirconium
dimethylsilanediylbis(2,4,7-trimethylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-5-isobutylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-5-t-butylindenyl)dimethylzirconium
dimethylsilanediylbis(2-methyl-4-phenanthrylindenyl)dimethylzirconium
dimethylsilanediylbis(2-ethyl-4-phenanthrylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4,6-diisopropylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4-isopropylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4,5-(methylbenzo)indenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4,5-(tetramethylbenzo)indenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4-xcex1-acenaphthindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-5-isobutylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-methyl-4-phenanthrylindenyl)dimethylzirconium
methyl(phenyl)silanediylbis(2-ethyl-4-phenanthrylindenyl)dimethyl zirconium
1,2-ethanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium
1,2-butanediylbis(2-methyl-4-phenylindenyl)dimethylzirconium
1,2-thanediylbis(2-methyl-4,6-diisopropylindenyl)dimethylzirconium
1,4-butanediylbis(2-methyl-4-isopropylindenyl)dimethylzirconium
1,4-butanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium
1,2-ethanediylbis(2-methyl-4,5-benzoindenyl)dimethylzirconium
1,2-ethanediylbis(2,4,7-trimethylindenyl)dimethylzirconium
1,4-butanediylbis(2-methylindenyl)dimethylzirconium
Pariticular preference is given to:
dimethylsilanediylbis(2-methylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(1-naphthyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-phenylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-(p-tert-butylphenyl)indenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-xcex1-acenaphthindenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-phenylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4,5-benzoindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4,6-diisopropylindenyl)zirconium dichloride
dimethylsilanediylbis(2-methyl-4-phenanthrylindenyl)zirconium dichloride
dimethylsilanediylbis(2-ethyl-4-phenanthrylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-methyl-4-phenanthrylindenyl)zirconium dichloride
methyl(phenyl)silanediylbis(2-ethyl-4-phenanthrylindenyl)zirconium dichloride
Methods of preparing metallocenes of the formula I are described, for example, in Journal of Organometallic Chem. 288 (1985) 63-67 and the documents cited therein.
As cocatalyst component B), the catalyst system of the present invention usually further comprises open-chain or cyclic aluminoxane compounds and/or other compounds B) capable of forming metallocenium ions. These can be Lewis acids and/or ionic compounds having noncoordinating anions.
The aluminoxane compounds are usually described by the formula II or III 
where
R21 is a C1-C4-alkyl group, preferably a methyl or ethyl group, and m is an integer from 5 to 30, preferably from 10 to 25.
The preparation of these oligomeric aluminoxane compounds is usually carried out by reacting a solution of trialkylaluminum with water and is described, for example, in EP-A 284 708 and U.S. Pat. No. 4,794,096.
In general, the oligomeric aluminoxane compounds obtained are in the form of mixtures of both linear and cyclic chain molecules of various lengths, so that m is to be regarded as a mean. The aluminoxane compounds can also be present in admixture with other metal alkyls, preferably aluminum alkyls.
Further compounds which can be used as component B) are aryloxyaluminoxanes as described in U.S. Pat. No. 5,391,793, aminoaluminoxanes as described in U.S. Pat. No. 5,371,260, aminoaluminoxane hydrochlorides as described in EP-A 633 264, siloxyaluminoxanes as described in EP-A 621 279 or mixtures thereof.
As Lewis acid, preference is given to using at least one organoboron or organoaluminum compound containing C1-C20 groups such as branched or unbranched alkyl or haloalkyl, e.g. methyl, propyl, isopropyl, isobutyl, trifluoromethyl, unsaturated groups such as aryl or haloaryl, e.g. phenyl, tolyl, benzyl, p-fluorophenyl, 3,5-difluorophenyl, pentachlorophenyl, pentafluorophenyl, 3,4,5-trifluorophenyl and 3,5-di(trifluoromethyl)phenyl.
Particular preference is given to organoboron compounds.
Examples of Lewis acids are trifluoroborane, triphenylborane, tris(4-fluorophenyl)borane, tris(3,5-difluorophenyl)borane, tris(4-fluoromethylphenyl)borane, tris(pentafluorophenyl)borane, tris(tolyl)borane, tris(3,5-dimethylphenyl)borane, tris(3,5-dimethylfluorophenyl)borane and/or tris(3,4,5-trifluorophenyl)borane. Particular preference is given to tris(pentafluorophenyl)borane.
Well-suited ionic compounds which contain a noncoordinating anion are, for example, tetrakis(pentafluorophenyl)borate, tetraphenylborate, SbF6xe2x88x92, CF3SO3xe2x88x92 or CIO4xe2x88x92. As cationic counterion, use is generally made of Lewis bases such as methylamine, aniline, dimethylamine, diethylamine, N-methylaniline, diphenylamine, N,N-dimethylaniline, trimethylamine, triethylamine, tri-n-butylamine, methyldiphenylamine, pyridine, p-bromo-N,N-dimethylaniline, p-nitro-N,N-dimethylaniline, triethylphosphine, triphenylphosphine, diphenylphosphine, tetrahydrothiophene and triphenylcarbenium.
Examples of such ionic compounds which have noncoordinating anions and can be used for the purposes of the present invention are
triethylammonium tetra(phenyl)borate,
tributylammonium tetra(phenyl)borate,
trimethylammonium tetra(tolyl)borate,
tributylammonium tetra(tolyl)borate,
tributylammonium tetra(pentafluorophenyl)borate,
tributylammonium tetra(pentafluorophenyl)aluminate,
tripropylammonium tetra(dimethylphenyl)borate,
tributylammonium tetra(trifluoromethylphenyl)borate,
tributylammonium tetra(4-fluorophenyl)borate,
N,N-imethylanilinium tetra(phenyl)borate,
N,N-diethylanilinium tetra(phenyl)borate,
N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,
N,N-dimethylanilinium tetrakis(pentafluorophenyl)aluminate,
di(propyl)ammonium tetrakis (pentafluorophenyl)borate,
di(cyclohexyl)ammonium tetrakis(pentafluorophenyl)borate,
triphenylphosphonium tetrakis(phenyl)borate,
triethylphosphonium tetrakis(phenyl)borate,
diphenylphosphonium tetrakis(phenyl)borate,
tri(methylphenyl)phosphonium tetrakis(phenyl)borate,
tri(dimethylphenyl)phosphonium tetrakis(phenyl)borate,
triphenylcarbenium tetrakis(pentafluorophenyl)borate,
triphenylcarbenium tetrakis(pentafluorophenyl)aluminate,
triphenylcarbenium tetrakis(phenyl)aluminate,
ferrocenium tetrakis(pentafluorophenyl)borate and/or
ferrocenium tetrakis(pentafluorophenyl)aluminate.
Preference is given to triphenylcarbenium tetrakis(pentafluorophenyl)borate and/or N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate.
It is also possible to use mixtures of at least one Lewis acid and at least one ionic compound.
Further use for cocatalyst components are borane or carborane compounds such as
7,8-dicarbaundecaborane(13),
undecahydrido-7,8-dimethyl-7,8-dicarbaundecaborane,
dodecahydrido-1-phenyl-1,3-dicarbaundecaborane,
tri(butyl)ammonium decahydrido-8-thyl-7,9-dicarbaundecaborate,
4-carbanonaborane(14),
bis(tri(butyl)ammonium) nonaborate,
bis(tri(butyl)ammonium) undecaborate,
bis(tri(butyl)ammonium) dodecaborate,
bis(tri(butyl)ammonium) decachlorodecaborate,
tri(butyl)aamonium 1-carbadecaborate,
tri(butyl)ammonium 1-carbadodecaborate,
tri(butyl)ammonium 1-trimethylsilyl-1-carbadecaborate,
tri(butyl)ammonium bis(nonahydrido-1,3-dicarbanonaborato)cobaltate(III),
tri(butyl)ammonium bis(undecahydrido-7,8-dicarbaundecaborato)ferrate(III)
The support component C) of the catalyst system used according to the present invention can be any organic or inorganic, inert solid, in particular a porous support such as talc, inorganic oxides and finely divided polymer powder (e.g. polyolefins).
Suitable inorganic oxides are those of elements of groups 2, 3, 4, 5, 13, 14, 15 and 16 of the Periodic Table of the Elements. Examples of oxides preferred as supports include silicon dioxide, aluminum oxide and also mixed oxides of the two elements and corresponding oxide mixtures. Other inorganic oxides which can be used alone or in combination with the last-named preferred oxidic supports are, for example, MgO, ZrO2, TiO2 or B2O3, to name only a few.
Organic support materials are, for example, finely divided polyolefin powders (e.g. polyethylene, polypropylene or polystyrene).
The support materials used, in particular the inorganic oxides, generally have a specific surface area in the range from 10 to 1000 m2/g, a pore volume in the range from 0.1 to 5 ml/g and a mean particle size of from 1 to 500 mm. Preference is given to supports having a specific surface area in the range from 50 to 500 m2/g, a pore volume in the range from 0.5 to 3.5 ml/g and a mean particle size in the range from 5 to 350 mm. Particular preference is given to supports having a specific surface area in the range from 200 to 400 m2/g, a pore volume in the range from 0.8 to 3.0 ml/g and a mean particle size of from 10 to 200 mm.
The preparation of the supported catalyst is generally not critical. Useful variants are the following:
In variant 1, in general at least one metallocene component A), usually in an organic solvent, is brought into contact with the cocatalyst component B) to give a dissolved or partly suspended product. This product is then generally added to the support material, which may have been pretreated as described above, preferably porous silicon dioxide (silica gel), the solvent is removed and the supported catalyst is obtained as a free-flowing solid. The supported catalyst can then be additionally prepolymerized, for example using C2-C10-alk-l-enes.
In variant 2, the supported metallocene catalyst is generally obtained by means of the following process steps
a) reaction of an inorganic support material, preferably porous silicon dioxide as described above, with a passivating agent, as described above, preferably a tri-C1-C10-alkylaluminum such as trimethylaluminum, triethylaluminum or triisobutylaluminum,
b) reaction of the material obtained in this way with a metallocone complex A), preferably a metallocone complex of the formula I, in fine metal dihaldide form and a compound B) capable of forming metallocenium ions, and subsequent
c) reaction with an organometallic compound of an alkali metal, alkali earth metal or element of main group III, preferably a tri-C1-C10-alkylaluminum such as trimethylaluminum, triethylaluminum or triisobutylaluminum.
This process is described in detail in DE-A 19 606 197, which is hereby expressly incorporated by reference.
As additive, a small amount of an olefin, preferably a 1-olefin such as 1-hexene or styrene, as activity-promoting component or an antistatic can be added during or after the preparation of the supported catalyst system. The molar ratio of additive to metallocene component (compound I) is preferably from 1:1000 to 1000:1, very particularly preferably from 1:20 to 20:1.
The supported catalyst system prepared according to the present invention can either be used directly for the polymerization of olefins or can be prepolymerized using one or more olefinic monomers before it is used in a polymerization process. The method of carrying out the prepolymerization of supported catalyst systems is described in WO 94/28034.
The polymers of the present invention can advantageously be converted into fibers, films and moldings.
The moldings, in particular the tubes, can be advantageously used in the construction of chemical apparatus, as drinking water pipes or as wastewater pipes.
Furthermore, the moldings comprising the propylene polymers of the present invention can be used for producing semifinished parts (examples are rods, plates, fittings, profiles, e.g. via an injection-molding process) or blow-molded containers or air conduits in the motor vehicle sector.